Membrane switch having adhesive label as edge seal

• US 4,375,018 A
• Filed: 06/16/1980
• Issued: 02/22/1983
• Est. Priority Date: 06/16/1980
• Status: Expired due to Term

• Current Assignee: Sheldahl, Inc.
• Original Assignee: Sheldahl, Inc.
• Inventors: Petersen, Stephen K.
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US06/159,954
• Time in Patent Office: 981 Days
• Field of Search: 200/5 A, 200/5 R, 200/159 B, 200/307, 200/308, 200/317, 200/1 R
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 2201/026 non precious
• CPC Class Codes: H01H 2207/01 from bottom to top layer
• CPC Class Codes: H01H 2209/08 with memory properties
• CPC Class Codes: H01H 2219/008 Adhesive
• CPC Class Codes: H01H 2223/022 Adhesive
• CPC Class Codes: H01H 2229/034 Positioning of layers
• CPC Class Codes: H01H 2229/036 ultrasonic
• CPC Class Codes: H01H 2229/038 Folding of flexible printed circuit

Abstract

A membrane switch comprised of first and second flexible layers having corresponding patterns of metallization thereon, these layers being separated by an apertured spacer. The first layer is of a larger size than the spacer and the second layer is of a smaller size than the spacer so that when the three are superposed, a border on the first layer and spacer are exposed to meet the second layer. Completing the assembly is a label layer which is of a flexible, non-conductive material having a desired pattern of graphics printed on it and an adhesive coated undersurface. When the label layer is pressed against the exposed surface of the second substrate, it bonds all three of the lower layers together and creates a seal around the perimeter of the switch assembly. With the label layer being of a greater size than the other three layers, it may also be used to affix the composite switch to the appliance on which it would be used.

Claims

1. A membrane switch comprising:

(a) a first substrate member formed from a flexible insulative material having a first pattern of conductive elements at predetermined coordinate locations thereon;

(b) an insulative spacer member superimposed on said first substrate member and having a pattern of apertures therethrough at said predetermined coordinate locations, said spacer member being of a smaller size such that when superimposed on said first substrate member with said pattern of apertures aligned with said first pattern of conductive elements, a predetermined area of said first substrate member proximate the periphery thereof extends outwardly beyond the edges of said spacer member;

(c) a second substrate member formed from a flexible insulative material superimposed on said spacer member having a second pattern of conductive elements at predetermined coordinate locations corresponding to said predetermined coordinate locations of said apertures on said spacer member, said second substrate being of a smaller size than said spacer member such that when superimposed on said spacer member with said second pattern of conductive elements aligned with said apertures, a predetermined area of said spacer member proximate the perimeter thereof extends outwardly beyond the edges of said second substrate member; and

(d) a flexible insulative cover layer overlying said superimposed members in superficial engagement with at least peripheral portions thereof, and having an adhesive coating on one major surface thereof for individually bonding and sealing at least perimeter portions of said second substrate, said spacer member and said first substrate member to said cover layer.

2. A membrane switch as in claim 1 wherein said first and second substrate members are joined by an integrally formed strip, said strip being folded so that said patterns of conductive elements on said first and second substrate members are aligned with said apertures in said spacer member, the width of said integrally formed strip being substantially less than the widths of said substrate members joined thereby.

3. A membrane switch comprising at least a pair of superimposed thin flexible members, the lower member being of greater area than the upper member to extend therebeyond peripherally;

(a) and a thin flexible cover layer overlying said members and adhesively secured to at least a peripheral portion of each said member to individually bond said members to said cover layer.

4. A membrane switch comprising a plurality of superimposed thin flexible members, each lower member being of greater area than any upper member above it to extend therebeyond peripherally,

(a) and a thin flexible cover layer overlying said plurality of members and adhesively secured to at least a peripheral portion of each said member to individually bond said members to said cover layer.